2. Field of the Invention
The subject invention relates to transport channels and to methods for facilitating service access to such transport channels.
2. Disclosure Statement
The following disclosure statement is made pursuant to the duty of disclosure imposed by law and formulated in 37 CFR 1.56(a). No representation is hereby made that information thus disclosed in fact constitutes prior art, inasmuch as 37 CFR 1.56(l) relies on a materiality concept which depends on uncertain and inevitably subjective elements of substantial likelihood and reasonableness and inasmuch as a growing attitude appears to require citation of material which might lead to a discovery of pertinent material though not necessarily being of itself pertinent. Also, the following comments contain conclusions and observations which have only been drawn or become apparent after conception of the subject invention or its merits contrast the subject invetion or its merits against the background of developments which may be subsequent in time or priority.
Transport channels are present in various apparatus, including, for instance, document, sheet or paper conveyors or feeders, document, sheet or paper handling or processing systems, copying apparatus, office machines, and other material handling equipment.
By way of background, reference may be had to U.S. Pat. No. 540,240, by T. C. Dexter, issued June 4, 1895 and showing apparatus for conveying sheets of paper having adjustable brackets for selectively tightening and slackening conveyor tapes for servicing purposes. In U.S. Pat. No. 1,668,816, by C. L. Low, issured May 8, 1928, a top holddown mechanism for a paper feeder is provided with a yoke that is releasably mounted on a crossbar in proximity to a paper conveyor. The yoke is equipped with a set screw which is tightened for attaching the yoke to the crossbar, and which is loosened for a removal of the top holddown mechanism from the paper feeder conveyor. In practice, such set screws generally present an inconvenience to operator and service personnel and also tend to become loose during operation of the sheet transport or feeder.
The U.S. Pat. No. 3,265,385, by E. F. C. Schulze, issued Aug. 9, 1966, disclosed a document feeding apparatus having a removable idler roller assembly held down and selectively released by spring clips. In practice, such spring clips often represent an inconvenience to the operator or to service personnel.
U.S. Pat. No. 3,628,786, by T. O. Maloney et al., issued Dec. 21, 1971, shows a document handling apparatus having a movable coverplate pivotally supported for access to components inside the document handling apparatus. A pivotal support is also shown in U.S. Pat. No. 3,661,383, by D. I. Morrison, issued May 9, 1972 for document handling apparatus having a cover and feed deck hinged for increased accessibility to the remainder of the apparatus. A spring-biased hinge separator gate is apparent from U.S. Pat. No. 4,113,244, by K. Ruenzi, issued Sept. 12, 1978. Hinged or pivoted sheet guideplates in sheet transport apparatus are also seen in Japanese Patent Application No. 52-38225 by T. Yano, published Mar. 24, 1977 and Japanese Patent Application No. 55-52840, by K. Miyamoto, published Apr. 17, 1980. While hinging mechanisms employing a shaft or similar pivot member sometimes represent a design convenience, they often present certain inconveniences when ready access to, or swift removal of objects from, the particular apparatus is desired.
Use of relatively complex pantograph-type and other lever mechanisms to provide service access to the inside of copying apparatus is illustrated in U.S. Pat. No. 4,116,556, by S. Tanaka et al., issued Sept. 26, 1978. British Patent Specification 1,583,168, by J. H. Cook, published Jan. 21, 1981 illustrates use of a drawer-slide member for achieving selective separation of guide plates for a removal of trapped sheets. While such approaches are meritorious in some applications, they tend to introduce complexities and limitations in others.